- Invasive Species Management
Invasive Species Management
Current Topics
- Weed of the Month
- Monthly Work Plan - Noxious Weeds for Landowners
- Blog - Annual weed control
Need Noxious Weed Advice?
We are able to answer calls and questions. Our hours are Mon -Thur 6:30 am - 5 pm. See our contact information on the right-hand side of this page.
What We Do
The Jefferson County Invasive Species Management program provides the public with information and offers solutions for managing invasive species and supports good stewardship of the land.
We ensure the compliance with Colorado’s noxious weed, forest pest, and agricultural vertebrate pest regulations on private, county, and state lands. We also provide technical assistance and support to county departments who are responsible for managing county owned lands.
The program coordinates with private, local, state, and federal agencies to achieve regional pest control.
Who We Are
Our staff includes the Invasive Species Management Coordinator and limited summer help.
Weed of the Month
Each month we will feature a noxious weed to help landowners identify weeds they may encounter on their property.
Houndstongue
May 2022
Houndstongue
Cynoglossum officinale
Houndstongue is a member of the Boraginaceae family. It is usually a biennial but occasionally acts as a short-lived perennial. It has hairy oblong leaves that form a rosette the first year. In early-spring to mid-summer in its second year, it starts to bolt. Between 1-8 stems grow from the crown. They can reach a height of 40+ inches. The stems have reduced leaves. Purple to magenta, five-lobed flowers are arranged loosely along the flower stem. Each flower is less than 4/10 inch wide and when mature, forms a four-parted seed head called a nutlet. Each nutlet contains one seed. The nutlets are covered with barbs that can latch onto fur, gear, and equipment.
The plants have a deep (to 40 inches), thick taproot but are easy to pull when very young. If the plants have started to bud, they should be securely bagged and thrown in the trash. Houndstongue is also easily controlled with herbicide if treated pre-flower.
Most (~75%) seeds fall within a few inches of the mother plant. Longer dispersal distances are via animals.
Known since 1830 in the US and 1897 in Colorado, Houndstongue is originally from Eurasia. It is thought to have arrived in North America in contaminated cereal seed. It is not strongly competitive but takes advantage of disturbance.
Houndstongue contains pyrrolizidine alkaloids and is poisonous to livestock. These alkaloids may be found in higher levels at the rosette stage. Animals tend to avoid live plants but when it is found in dried hay livestock will consume enough to be affected.
Resources
National Invasive Species Information Center
Images
Root - John M. Randall, The Nature Conservancy, Bugwood.org
Shoe - K. George Beck and James Sebastian, Colorado State University, Bugwood.org
Flower - Joseph M. DiTomaso, University of California - Davis, Bugwood.org
Native Grass Profiles
Western Wheatgrass
(Pascoplyrum smithii)
Photos courtesy of bugwood.org
Western wheatgrass is a long-lived perennial grass that likes sunny, dry, sandy sites. Its elevation range is between 3000 and 9500 feet.
This cool-season grass grows erect to 30 inches tall and has rhizomes that form sod. The narrow (about ¼ inch wide) leaf blades are blue-gray to green and are stiff with a mid-rib.
This grass flowers in June-August. The flowers are arranged in 4- to 6-inch-long heads.
The ligule is fibrous and reduced. The auricles are purplish and clasp the stem.
The best time to plant is mid-March through mid-April.
Western wheatgrass is used as forage for livestock and wildlife. Because of its root structure it is used in revegetation projects and as a soil stabilization species.
A Landowner's Guide - Developing a Noxious Weed Management Plan
We developed this guide to assist landowners. The information provides steps to develop a management plan for properties that have noxious weeds.
Weed Spotter
The Weed Spotter program is a citizen science based effort to detect 6 high priority species on Jeffco Open Space parks. Learn more at our Citizen Science page.
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Invasive Species Management
Physical Address
700 Jefferson County Parkway, Suite 100
Golden, CO 80401
Phone: 303-271-5989
Hours
Monday - Thursday
6:30 a.m. - 5:00 p.m.
Notices
Noxious Weed Treatments
Jefferson County Open Space will be applying herbicides for noxious weed control at the following parks.
Please give our crews and contractors room to work.
Dates and locations subject to change.
Always visit the main kiosk at the individual park for current information.
Week of 5/23
- Apex Park
- Crown Hill Park
- Van Bibber Park
Week of 5/16
Trailheads
- Elk Meadow Park
- Meyer Ranch Park
- Pine Valley Ranch Park
- Reynolds Park
Parks
- Hildebrand Ranch Park
- South Valley Park
Ongoing
Ongoing
During 2022, in addition to our normal noxious weed treatments, we will be performing forest restoration work at these locations. We will be treating parts of the sites with herbicides throughout the season. The maps below show the work areas within the parks.
Alderfer Three Sisters Map (pdf)